Inflatable medical balloons with continuous fiber wind

ABSTRACT

A fiber-reinforced device, such as an inflatable medical balloon, includes a cylindrical central portion ( 1301 ). The balloon includes first and second tapered or conical end portions ( 1303   a,   1303   b ) connected to the cylindrical central portion along a central longitudinal axis extending from a first end of the balloon to a second end of the balloon. In one embodiment, the balloon includes a single continuous fiber ( 1313   a ) running substantially parallel to the longitudinal axis along the central portion and radially around a portion of the end portions, or both. The balloon comprises a second fiber ( 1315 ) extending radially around the central portion of the balloon, which may be part of the single continuous fiber. Related methods are described.

INCORPORATION BY REFERENCE

All publications and patent applications mentioned in this specificationare herein incorporated by reference to the same extent as if eachindividual publication or patent application was specifically andindividually indicated to be incorporated by reference. This applicationalso incorporates herein by reference U.S. Provisional PatentApplication Ser. No. 61/815,689 and U.S. Provisional Patent ApplicationSer. No. 61/656,404.

BACKGROUND

Fiber based devices and expandable devices, such as balloons, are widelyused in medical procedures. In the case of a balloon, it is inserted,typically on the end of a catheter, until the balloon reaches the areaof interest. Adding pressure to the balloon causes the balloon toinflate. In one variation of use, the balloon creates a space inside thebody when the balloon inflates.

Balloons may be used in the heart valves, including during BalloonAortic Valvuloplasty (BAV) and Transcatheter Aortic Valve Implantation(TAVI). The balloons can be used to open a stenosed aortic valve. Astenosed valve may have hard calcific lesions which may tend to tear orpuncture a balloon. Additionally, a precise inflated balloon diametermay be desired for increased safety and control.

Balloons may be used to move plaque away from the center of a vascularlumen toward the vasculature walls, such as during an angioplasty or aperipheral vasculature procedure. During this procedure, a balloontipped catheter is placed in a vascular obstruction. As the balloon isinflated, the vessel constriction is dilated, resulting in improvedblood flow.

Two basic types of balloons are utilized: One is a high pressure,low-compliance balloon. The other is a lower pressure, high-complianceballoon.

High-compliance medical balloons are often composed of urethane, latex,silicone, PVC, Pebax, and other elastomers. As the pressure in ahigh-compliant balloon is increased, the balloon dimensions expand. Oncethe pressure is reduced, the high-compliance medical balloon may returnto its original shape, or near its original shape. High-compliancemedical balloons can easily expand several times in volume between zeroinflation pressure and burst.

Traditional high-compliance medical balloons can be inadequate for manyreasons. High-compliance, or highly elastic medical balloons typicallycannot reach high pressures because their walls have a low tensilestrength and their walls thin out as the balloon expands. In someinstances, high-compliance medical balloons provide insufficient forceto complete a procedure. Exceeding the rated pressure of ahigh-compliance medical balloon creates an excessive risk of balloonfailure which can lead to serious complications for the patient.Moreover, high-compliance medical balloons also have poor shape control.As a high-compliance medical balloon expands, it may assume a shapedictated mostly by the particulars of the environment inside the patientrather than the clinical goals. In some cases, this can be contrary towhat the medical practitioner desires. Many medical procedures arepredicated on forming a particular balloon shape reliably. Further,high-compliance medical balloons often suffer from poor puncture andtear resistance.

Low-compliance, high pressure medical balloons substantially retaintheir shape under comparatively high pressures. PET (polyethyleneterephthalate) is the most common material for use in high pressurelow-compliance balloons. PET is commonly used for high-performanceangioplasty balloons. PET is stronger than other polymers, can be moldedinto a variety of shapes and can be made very thin (e.g., 5 μm to 50 μm(0.0002 in. to 0.002 in.)), thus giving these balloons a low profile.However, balloons made from PET walls are fragile and prone to tears.When pressed against a hard or sharp surface in the body, such asstenosis, PET balloons have poor puncture resistance. PET is very stiffso balloons made from PET may be difficult to pack or fold into a smalldiameter and may have poor trackability (i.e., the ability to slide andbend over a guidewire deployed through a tortuous vessel). Further,balloons made from PET, while stronger than most other balloons madefrom homogenous polymers, may still not be strong enough to holdpressures sufficient to complete certain medical procedures.Additionally, with a large balloon diameter (For example, 20 mm orgreater), a PET balloon still has excessive compliance for proceduressuch as BAV and TAVI. Nylon balloons are an alternative material forlow-compliance, high pressure balloons. However, these nylon balloonsare typically weaker than PET balloons and so can contain less pressure.Nylon readily absorbs water, which can have an adverse effect on Nylon'smaterial properties in some circumstances. Nylon has improved punctureresistance over PET and is more flexible than PET.

Fiber-reinforced composite balloons are another alternativelow-compliance, high pressure medical balloon. Such fiber-reinforcedcomposite balloons can advantageously sustain high pressures, providedprecise shape control, and are highly resistant to tear and puncture.The manufacturing process for fiber-reinforced balloons, however, can becomplicated and expensive, requiring the application of multipledifferent layers of fibers in order to achieve the desired support.Often, at least one of these layers consists of a fabric de-convolutionpattern layer wrapped around a base balloon. Such forming and wrappingof the fabric pattern layer can be cumbersome, labor and equipmentintensive, and time consuming. Further, depending upon the orientationof the fibers, the tear pattern of a fiber-reinforced balloon (sometimesreferred to as its “rip” or “rip-stop” properties) upon bursting canresult in enhanced difficulties in removing the balloon through a shaft.

Thus, there exists the need to create a fiber-reinforced device, such asa balloon, that can be manufactured quickly and easily while stillmaintaining its ability to withstand high pressures, provide preciseshape control, and have highly controlled tear properties.

SUMMARY OF THE DISCLOSURE

In general, in one embodiment, a medical apparatus comprises a deviceincluding a single continuous fiber extending both radially andlongitudinally. In one example, the device may be a balloon including acentral portion and first and second tapered portions connected to thecentral portion along a longitudinal axis extending from a first end ofthe balloon to a second end of the balloon. The single continuous fibermay extend substantially parallel to the longitudinal axis along thecentral portion and radially around at least a portion of at least oneof the first and second tapered portions of the device.

The apparatus may further include a second fiber extending radiallyaround the central portion of the balloon. The second fiber may be partof the single continuous fiber, which may comprise a plurality of firstfiber strands. Each strand of the plurality of first fiber strands mayextend at an angle of approximately 35-90 degrees relative to thelongitudinal axis of the balloon as the strands extend radially aroundat least a portion of the first and second tapered portions. Each strandof the plurality of first fiber strands may transition from extendingradially around at least a portion of the tapered portions to extendingsubstantially parallel with the longitudinal axis in the first andsecond tapered portions.

The second fiber may extend at an angle of approximately 80 to 90degrees relative to the longitudinal axis of the balloon as the secondfiber extends radially around the central portion. The second fiber mayextend around the first and second tapered portions at a lower pitchthan a pitch of the second fiber strand around the central portion. Thesecond fiber may extend over the first fiber, and may be over a firstportion of the first fiber and under a second portion of the firstfiber. The first portion of the first fiber may be on a first half ofthe balloon and the second portion of the first fiber is on a secondhalf of the balloon.

A third fiber may also be provided. The third fiber may start in thefirst tapered portion at a location separated from the first end of theballoon. The third fiber may be part of the single continuous firstfiber.

The single continuous fiber may extend radially around both the firstand second tapered portions of the balloon.

In other embodiments, a fiber-reinforced medical balloon includes acylindrical central portion. The balloon includes first and secondconical portions connected to the cylindrical central portion along acentral longitudinal axis extending from a first end of the balloon to asecond end of the balloon. The balloon includes a plurality of firstfiber strands extending from the first end of the balloon to the secondend of the balloon. Each strand of the plurality of first fiber strandsruns substantially parallel to the longitudinal axis through thecylindrical central portion and radially around at least a portion ofthe first and second conical portions. The balloon includes at least onesecond fiber strand extending radially around the central portion.

This and other embodiments can include one or more of the followingfeatures. The strands of the plurality of first fiber strands can be allpart of a single continuous fiber. The plurality of first fiber strandsand the at least one second fiber strand can be all part of a singlecontinuous fiber. Each strand of the plurality of first fiber strandscan extend at an angle of approximately 35-90 degrees relative to thelongitudinal axis of the balloon as the strands extend radially aroundat least a portion of the first and second conical portions. Each strandof the plurality of first fiber strands can transition from extendingradially around at least a portion of the conical portions to extendingsubstantially parallel with the longitudinal axis in the first andsecond conical portions. The at least one second fiber strand can extendat an angle of approximately 80 to 90 degrees relative to thelongitudinal axis of the balloon as the strand extends radially aroundthe central portion. The at least one second fiber strand can extendaround the first and second conical portions at a lower pitch than apitch of the at least one second fiber strand around the centralportion. The at least one second strand can extend over all of thestrands of the plurality of first fiber strands. The at least one secondstrand can extend over a first portion of the plurality of first fiberstrands and under a second portion of the plurality of first fiberstrands. The first portion of the plurality of first fibers can be on afirst half of the balloon and the second portion of the plurality offirst fibers can be on a second half of the balloon. Thefiber-reinforced medical balloon can further include a plurality ofthird fiber strands, the plurality of third fiber strands can start inthe first conical portion at a location separated from the first end ofthe balloon. At least a portion of the first fiber strands and the thirdfiber strands may be part of a single continuous fiber.

This disclosure also pertains to a medical apparatus in the form of aballoon including a central portion and first and second taperedportions connected to the central portion. The balloon includes alongitudinal axis extending from a first end of the balloon to a secondend of the balloon. A non-woven fiber layer includes a first fiberextending substantially parallel to the longitudinal axis along thecentral portion and a second fiber extending radially around the firsttapered portion. The first fiber and the second fiber may form part of asingle continuous fiber.

In general, in one embodiment, a method of making a fiber-reinforcedcomposite balloon having a cylindrical central portion and first andsecond tapered portions connected to the cylindrical central portionalong a central longitudinal axis extending from the first end of theballoon to the second end of the balloon is described. The methodincludes applying a single continuous fiber to the cylindrical centralportion extending substantially parallel to the longitudinal axis of theballoon, and applying the single continuous fiber to at least one of thefirst and second tapered portions. The applying step may includeapplying the single continuous fiber radially around at least a portionof at least one of the first and second tapered portions. The method mayfurther include applying a second fiber extending radially around thecentral portion of the balloon.

In another embodiment disclosed, a method of making a fiber-reinforcedcomposite balloon having a cylindrical central portion and first andsecond conical portions connected to the cylindrical central portionalong a central longitudinal axis extending from the first end of theballoon to the second end of the balloon, includes applying a singlecontinuous fiber to a base layer having the cylindrical central portionand first and second conical portions to form a plurality of first fiberstrands extending substantially parallel to the longitudinal axis of theballoon within the cylindrical central portion.

This and other embodiments can include one or more of the followingfeatures. Applying a single continuous fiber can include forming a fiberstrand of the plurality of first fiber strands by wrapping the fiberradially around the first conical portion, laying the fibersubstantially parallel to the longitudinal axis within the cylindricalcentral portion, and wrapping the fiber radially around the secondconical portion from the first end of the balloon to the second end ofthe balloon. Applying a single continuous fiber can further includeforming another fiber strand of the plurality of first fiber strands bychanging the direction of applying the fiber so as to wrap the fiberradially around the second conical portion, laying the fibersubstantially parallel to the longitudinal axis within the cylindricalcentral portion, and wrapping the fiber radially around the firstconical portion from the second end of the balloon to the first end ofthe balloon. The method can further include wrapping the fiber radiallyaround the cylindrical central portion to form at least one second fiberstrand. Wrapping the fiber radially around the cylindrical centralportion to form at least one second fiber strand can include wrappingthe fiber radially around the cylindrical portion over at least aportion of the strands of the plurality of first strands. The method canfurther include wrapping a second portion of the plurality of firstfiber strands over the at least one second fiber strand. Applying asingle continuous fiber can include dipping the fiber in a solvatedthermally weldable material to adhere the fiber to a bladder extendingover the base mandrel. The method can further include cutting off thefirst or second end of the balloon after applying the single continuousfiber.

The disclosure may be considered to pertain to a medical apparatus,comprising a device, such as a medical tube, including a singlecontinuous fiber applied longitudinally and radially to differentportions of the device. A related method of forming a fiber-based devicecomprises applying a single continuous fiber longitudinally and radiallyto different portions of the device. The disclosure also pertainsbroadly to a method of forming a fiber-based device by applying a singlecontinuous fiber longitudinally to a central portion of the device andradially to another portion of the device.

The disclosure may also pertain to a medical apparatus, comprising aballoon having a longitudinal axis, the balloon including a single fiberlayer including one or more fibers extending substantially parallel tothe longitudinal axis in one portion of the layer and substantially in adirection transverse to the longitudinal axis. In one embodiment, theballoon comprises a generally cylindrical portion along which fiberextends in alignment with the longitudinal axis and a generally taperedportion connected to the cylindrical portion, wherein fiber extends in aradial direction along the tapered portion. The fiber may be a singlecontinuous fiber.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the invention are set forth with particularity inthe claims that follow. A better understanding of the features andadvantages of the present invention will be obtained by reference to thefollowing detailed description that sets forth illustrative embodiments,in which the principles of the invention are utilized, and theaccompanying drawings of which:

FIG. 1 shows an inflatable device having longitudinal fiber strands anda hoop fiber strand. The longitudinal fiber strands extend substantiallyparallel to the longitudinal axis within the central portion andradially around the end portions of the balloon. The hoop fiber strandextends radially around the inflatable device along the length of thedevice.

FIG. 2 shows the application of a first longitudinal fiber strand to aninflatable device.

FIG. 3 shows the application of a second longitudinal fiber strand to aninflatable device.

FIG. 4 shows the application of a third longitudinal fiber strand to aninflatable device.

FIG. 5 shows the application of a fourth longitudinal fiber strand to aninflatable device.

FIG. 5a is a cross-section of the inflatable device of FIG. 5.

FIG. 6 shows longitudinal fibers extending all the way around thecircumference of an inflatable device.

FIG. 6a is a cross-section of the inflatable device of FIG. 6.

FIG. 7 shows a hoop strand wound around an inflatable device havinglongitudinal fiber strands thereon.

FIG. 7a is a cross-section of the inflatable device of FIG. 7.

FIG. 8 shows an inflatable device having longitudinal fiber strands laidover half of the inflatable device.

FIG. 8a is a cross-section of FIG. 8.

FIG. 9 shows a hoop strand wrapped around the device of FIG. 8.

FIG. 9a is a cross-section of FIG. 9.

FIG. 10 shows application of longitudinal fiber strands over the hoopstrand of FIG. 9. FIG. 10a is a cross-section of FIG. 10.

FIG. 11 is a cross-section of an inflatable device having groups oflongitudinal strands under a hoop fiber strand and other groups oflongitudinal strands over the hoop strand.

FIG. 12 shows longitudinal strands extending over an inflatable deviceat an angle to the longitudinal axis within a central portion of theinflatable device.

FIG. 13 shows a hoop strand wound over the inflatable device of FIG. 12.

FIG. 14 shows an exemplary fiber wind on an inflatable device where theradial wrap of the longitudinal strands extends at least half way up theconical portions of the inflatable device.

FIG. 15 shows a hoop strand wound over the inflatable device of FIG. 14.

FIG. 16 shows application of fiber strands to an inflatable device in acontinuous process with a tool wheel.

FIG. 17 shows exemplary layers or sections of the wall of an inflatabledevice.

FIGS. 18A-18G shows an exemplary method of making an inner layer orbladder for an inflatable device.

FIGS. 19A-B show an exemplary method for consolidating the layers orsections of an inflatable device.

DETAILED DESCRIPTION

In general, described herein is a fiber-reinforced device, such as amedical balloon, that is formed by the application of a continuous fiberwind. The balloon includes fiber or fiber strands extendingsubstantially parallel to the longitudinal axis within the centralportion and radially around the end portions of the balloon.

Referring to FIG. 1, an inflatable device 2 (e.g., balloon) can includea central portion 1301, tapered or conical portions 1303 a,b, and endportions 1305 a,b. The central portion 1301 and end portions 1305 a,bcan be, for example, cylindrical in shape with a substantially constantdiameter across the length of the respective portions 1301, 1305 a,b. Inother embodiments, either the central portion 1301 or the end portions1305 a,b can vary in diameter along the length of the respectiveportions, such as have a slightly necked configuration. Portions 1305a,b can be reduced in length or eliminated in some embodiments. Thefiber strands can also be longitudinal in end portions 1305 a, b, butare illustrated as being radial.

The conical portions 1303 a,b extending between the central portion 1301and the end portions 1305 a,b can have a cross-section of decreasingradius extending from the central portion 1301 to the end portions 1305a,b, i.e., can be in the shape of a cone. In some embodiments, theconical portions 1303 a,b can have areas of extension or distension,such as have a bulbous or rounded section therein. Further, the conicalportions 1303 a,b can each have subsections 1307 a,b and 1309 a,b.Subsections 1307 a, b can extend from the central portion 1301 and canhave a substantially convex outer surface while the subsections 1309 a,bcan extend from the end portions 1305 a,b and can have a substantiallyconcave outer surface. The respective convex and concave outer surfacescan advantageously provide for a smooth outer surface of the balloon,even at locations of quickly changing diameter.

As is further shown in FIG. 1, the inflatable device 2 may includelongitudinal fiber strands 1313 traversing the length of the inflatabledevice 2 from one end of the device to the other. Each longitudinalfiber strand 1313 can extend radially around the balloon at the ends ofthe balloon (e.g., in the end portions 1305 a,b or conical portions 1303a,b). Hence, the strand 1313 may be considered to form a fiber layer ofthe inflatable device 2, in which fiber within the layer extends both ina direction generally parallel to the longitudinal axis (such as alongthe cylindrical section) and in a direction generally transverse to thelongitudinal axis (such as along the end portion or portions 1305 a, b).The fiber strands 1313 can thus spiral or extend helically around theends of the inflatable device 2 at an angle of approximately 25-90degrees relative to the longitudinal axis 108 of the balloon, such as50-80 degrees, such as approximately 35 degrees, 40 degrees, 45 degrees,50 degrees, 55 degrees, 60 degrees, 65 degrees 70 degrees or 75 degrees.Each fiber strand 1313 can further extend substantially parallel (e.g.±5°, ±2°, ±1°, or ±0.1°) to the longitudinal axis 108 within the centralportion 1301. For example, each fiber strand 1313 can extendsubstantially parallel to the longitudinal axis 108 along the entirecentral portion 1301.

Referring still to FIG. 1, the inflatable device 2 can further includeat least one hoop fiber strand 1315. The hoop fiber strand 1315 can windradially around at least the central portion 1301. The hoop fiber strand1315 can extend at an angle of nearly 90 degrees relative to thelongitudinal axis 108, such as 80 to 90 degrees, and can extend at leastthe length of the entire central portion 1301. In some embodiments, thehoop fiber strand 1315 can extend through all or part of the conicalsections 1303 a,b and/or the end portions 1305 a,b. Further, inembodiments where the hoop fiber strand 1315 extends through all or partof the conical sections 1303 a,b and/or the end portions 1305 a,b, thepitch of the fiber wind can be higher (e.g. there can be more winds perinch) in the central portion 1301 than the pitch of the fiber windtowards the ends of the inflatable device 2. Advantageously, because thelongitudinal fiber strands 1313 are radially wound around at leastsections of the conical portions 1303 a,b and provide radial support,the hoop fiber strands 1315 need not extend fully over those sections(or at as high of a pitch).

Referring to FIGS. 2-7, in some embodiments, the strands 1313, 1315 canall be applied to the balloon as part of a single continuous fiber 85(which can be a single monofilament or a fiber tow including a pluralityof monofilaments). Referring to FIG. 2, the fiber 85 can be applied to amandrel configured with the shape of the inflatable element 2 (i.e. witha central portion 1301, conical portions 1303 a,b, and end portions1305,a,b). The mandrel can further include sacrificial shafts 2000 a,bextending from the ends of the inflatable element 2. The fiber 85 can bewrapped radially around the end portion 1305 b, radially around throughat least a portion of the conical portion 1303 b, laid across thecentral portion 1301 substantially parallel to the longitudinal axis108, and then extend down the cone portion 1303 a where it cantransition to wrapping radially around the cone portion 1303 a and endportion 1305 a. The first traverse across the length of the inflatableelement 2 can form a first fiber strand 1313 a.

Referring to FIG. 3, in order to form another fiber strand 1313 b, thefiber 85 can be directed back towards the inflatable element 2 andwrapped in the opposite direction (i.e., from the end portion 1305 a tothe end portion 1305 b). As shown in FIG. 3, the radial wrap (e.g.,spiral or helix) of the fiber strand 1313 b will extend opposite to thatof the radial wrap of the fiber strand 1313 a such that the strands 1313a,b meet or overlap a center point of each turn of the wrap. The fiberstrands 1313 a,b will further cross within the conical portion 1303 a,bbefore straightening out to extend substantially parallel to one anotherwithin the central portion 1301.

Referring to FIG. 4, a third fiber strand 1313 c can be applied bydirecting the fiber 85 back towards the inflatable element 2 and layingit down similar to fiber strand 1313 a. As shown in FIG. 4, the fiberstrand 1313 c will run substantially parallel with the fiber strand 1313a along both the central portion 1301 and the end portions 1305 a,b.Further, as shown in FIG. 4, the fiber strands 1313 can be laid downconsecutively such that fiber strand 1313 c is laid directly next tofiber strand 1313 b, which his laid directly next to fiber strand 1313a.

Referring to FIG. 5, a fourth fiber strand 1313 d can be applied bydirecting the fiber 85 back towards the inflatable element 2 and layingit down similar to fiber strand 1313 b. FIG. 5a shows a cross-section ofthe resulting fiber lay-out.

Referring to FIGS. 6 and 6 a, the fiber 85 can continue to be wound backand forth from one end of the inflatable device to the other end untilthe fiber strands 1313 have been laid all the way around thecircumference of the central portion 1301. The fiber strands 1313 can belaid down such that, when the entire circumference is covered, the fiberstrands 1313 are substantially evenly spaced from one another throughoutthe length of the balloon. Thus, as the diameter narrows, the spacingbetween fiber strands will be reduced in amount, but still staysubstantially even from fiber strand to fiber strand.

It should be understood that while only 12 strands 1313 have been shownaround the circumference of the central portion 1301 for claritypurposes, the pitch of the strands 1313 can be much higher. For example,the pitch of the strands 1313 can be between 8 and 100 pitch, morenarrowly, 30 and 50 pitch, such as approximately 40 pitch. Further,although the fiber strands were described as being laid downconsecutively, they need not be. For example, the strands 1313 might belaid down in separate groups.

In some embodiments, the hoop strand 1315 can be applied using the samecontinuous fiber 85. In one embodiment (shown in FIGS. 7 and 7 a), thehoop strand 1315 can be applied over all of the longitudinal strands1313. Thus, once the longitudinal strands 1313 have been wound, thefiber 85 can be directed back towards the inflatable device 2 and woundradially around the end portions 1305 a, b, the conical portions 1303a,b, and the central portion 1301 to form an overlaying hoop strand1315.

Referring to FIGS. 8-10, in one embodiment, rather than applying thehoop strand 1315 over all of the longitudinal strands 1313, a set of thelongitudinal strands 1313 can be placed down, followed by the hoopstrand 1315, followed by a second set of the longitudinal strands 1313.For example, as shown in FIGS. 8 and 8 a, the fiber 85 can be laid downalong half of the inflatable device 2 to form a first set 1321 ofstrands 1313. As shown in FIGS. 9 and 9 a, the fiber 85 can then beradially wound around at least the central portion 1301 to form the hoopstrand 1315 over the first set 1321. Finally, as shown in FIGS. 10 and10 a, the fiber 85 can be laid down along the second half of theinflatable device 2 to form a second set 1323 of strands 1313 over thehoop strand 1315. As a result, the first set of fibers 1321 (extendingalong one half of the balloon) are underneath the hoop strand 1315 whilea second set of strands 1323 are over the hoop strand 1315.

Alternate configurations are possible. For example, as shown in FIG. 11,a first set 1325 of the longitudinal strands 1313 could be laid down ina more spread out configuration (i.e. at half the pitch than is desiredfor the final device layup), then the hoop strand 1315 can be laid down,and then a second set 1327 of the longitudinal strands 1313 can be laiddown over the hoop strand 1315 and in between the previously laid downlongitudinal strands 1313. In this example, the first and second sets1325, 1327 of longitudinal fiber strands 1313 could be laid downsingularly or in groups (such as 1-10 longitudinal strands 1313 pergroup). In yet another example, the application of the hoop strand(s)can be separated by one or more application of longitudinal strands. Forexample, a hoop strand 1315 could be wound from one end to center over aset of longitudinal strands 1313, more longitudinal strands 1313 couldbe applied over the hoop strand 1315, and then another hoop strand 1315could laid down from the other end to center.

Referring to FIG. 12-13, in some embodiments, the longitudinal fiberstrands 1313 can extend at a slight angle relative to the longitudinalaxis 108 within the central portion 1301. For example, the fiber strands1313 can extend at an angle of +/−0 to 20 degrees relative to thelongitudinal axis, such as +/−5-15 degrees, such as, for instance, +/−12degrees. Further, every other fiber strand 1313 (or alternating groupsof fiber strands) can extend in opposite positive/negative directionsrelative to the longitudinal axis 108, thereby keeping the inflatabledevice 2 from twisting.

Referring to FIG. 14-15, in some embodiments, the longitudinal fibers1313 can extend radially around most or all of the concave subsections1309 a,b. Having the longitudinal fibers 1313 extending radially aroundthe concave subsections 1309 a,b can advantageously both help preventthe fiber strands from lifting up during or after application of thestrands (as fiber strands extending substantially parallel to thelongitudinal axis tend to want to lift up out of the concave section)and help prevent the fiber strands from falling down the steep angleduring or after (as fiber strands extending substantially perpendicularto the longitudinal axis tend to want to fall down the slope). In otherembodiments, the radial wind of the longitudinal strands 1313 can extendless than 1%, about 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100%of the length of the conical portions 1303 a,b.

In some embodiments, rather than having each longitudinal strand extendthe entire length of the inflatable device, the longitudinal strands canreverse or turn around in the conical portions. For example, some of thelongitudinal strands can reverse at the point where the rest of thelongitudinal fibers go from being substantially parallel to thelongitudinal axis to winding radially around. Advantageously, by havingsuch strands that reverse within the cone rather than extending all theway to the end of the balloon, there can be less build-up of fiber inthe ends of the cone.

In some embodiments, the longitudinal fiber strands 1313 can extendsubstantially parallel to the longitudinal axis 108 within the endportions 1305 a,b. Thus, each strand can extend substantially parallelto the longitudinal axis 108 within the central portion 1301, radiallyaround at least part of the conical portions 1303 a,b, and substantiallyparallel to the longitudinal axis 108 within the end portions 1305 a,b.

The sacrificial shafts 2000 a,b can be removed after all of the fiberhas been applied. In some embodiments, a portion of the inflatabledevice and/or shaft over which fiber has been applied can be cut off.Doing so can advantageously remove unnecessary thickness at theturnarounds. Thus, during application, the turnaround point for some orall of the strands 1313 (i.e. the connection from one strand to the nextstrand) can be laid down either over the sacrificial shafts 2000 a,b orover the inflatable device 2 itself. In FIGS. 2-10 and 12-16, the fiberis shown as extending over the sacrificial shaft 2000 b and endingbefore the sacrificial shaft 2000 a.

The fiber strands described herein can be part of a fiber matrix, suchas fibers extending within a resin, adhesive, or thermally weldablematerial (such as a TPU). The resin, adhesive, or thermally weldablematerial may be applied to the fibers before, during, or after thefibers are placed on the inflatable device 2.

The inflatable device 2 described herein can include additional radialsections aside from those described herein. For example, referring toFIG. 17, the inflatable device can include a wall 1331 having an outerlayer 72 a, such as a polymer film. The wall 1331 can further include aninner layer 72 b, which can be a leak proof bladder made from a polymerfilm. The first middle layer 72 c can be a fiber matrix, for examplewith the fibers 1313 as described above. The second middle layer 72 dcan be a fiber matrix, for example with the strands 1315 oriented bothradially and parallel as described above. Additionally, as describedabove, the matrix layers 72 c, 72 d can be merged together into a singlelayer by having the hoop strands 1315 extend over some of thelongitudinal strands 1313 and under other longitudinal strands 1313.Alternatively, the matrix layers 72 c, 72 d can be switched inorientation relative to one another. The third middle layer 72 e can bea resin or adhesive or thermally weldable material. The outer layer 72 amay serve to isolate and protect the strands 1313, 1315.

To manufacture the entire balloon wall 1331, a bladder can first becreated. For example, referring to FIGS. 18A-18G, the bladder can bemade over a mandrel 230 having the shape of the inflatable device 2(i.e., a central portion, conical portions, and end portions). FIG. 18Aillustrates that the outer surface of the mandrel 230 can have some glueor first adhesive 208 a. The first adhesive 208 a can be located aroundthe perimeter of the first panel's 196 a contact area with the mandrel.The first adhesive 208 a can be water soluble. The first adhesive 208 acan be a sugar syrup. A panel 196 a may be positioned over the mandrel.The panel 196 a may be a single layer or multiple layers. For instance,the panel could be a layer of film and meltable adhesive. The panel 196a can be positioned with film on the side that touches the mandrel andadhesive on the radially outer side. The panel 196 a may be perforated.The panel may not be capable of sustaining pressure between the top andbottom of the panel.

FIG. 18B illustrates that a positive pressure can be applied to the topof a pressure chamber and/or a negative pressure or differentialpressure or suction or vacuum applied to the bottom of a pressurechamber. As a result, the panel 196 a can get sucked and/or pressed downand/or formed onto the mandrel 230. Forming of the panel 196 a may causeportions of panel 196 a to yield or stretch or deform or become thinneror combinations thereof. For instance, more than about 25% of the panel196 a covering central section 38 may have been significantly yieldedand/or stretched during the forming operation. The first panel can besmoothly fitted to the mandrel 230 and adhered to the mandrel at thefirst adhesive 208A. Heat may be applied to panel 196 a before formingonto mandrel 230. Forming of one panel 196 a may be done more than onceon different sized mandrels before the panel 196 a reaches the formshown in FIG. 18B. Forming of panel 196 a may also be accomplished witha mechanical die. The mechanical die may be heated and conform closelyto the shape of the mandrel 230. The mechanical die may have a shapesimilar to the mandrel. The mandrel 230 and panel 196 a can be mountedinto a trimming jig. Any excess portion of the first panel 196 aextending from the mandrel 230 can be trimmed with a blade, with alaser, with a water jet cutter, with a die cut tool or combinationsthereof. The trimming jig can cover the mandrel 230 and the first panel196 a attached to the mandrel. Several panels 196 a and/or layers 72 canbe formed over the mandrel 230 and cut. The panels 196 a and/or layers72 may be trimmed at the same time or one at time.

FIG. 18C illustrates that the mandrel can have the excess area of thefirst panel 196 a removed in preparation for attachment of the secondpanel 196 b.

FIG. 18D illustrates that a second adhesive 208 b can be applied to thefirst panel 196 a around the perimeter of the second panel's 196 bcontact area with the first panel 196 a. The second adhesive 208 b canbe an epoxy, urethane, a thermoplastic, a cyanoacrylate, a UV curingadhesive, or combinations thereof. The mandrel 230 can be seated in amandrel seat with the first panel 196 a in the mandrel seat. The secondpanel 196 b can be placed on the mandrel 230 as shown.

FIG. 18E illustrates that positive and/or negative pressures can beapplied to the pressure chamber as described infra. The second panel 196b can be smoothly fitted or pressure formed to or against the mandrel230 and adhered to the first panel 196 a at the second adhesive 208 b.Adhesion can be accomplished by the application of heat. The first andsecond panels (196 a and 196 b) can form the inner layer 72 b or bladder52 of the balloon wall. The inner layer may be leak tight. The innerlayer may be capable of sustaining pressure. Multiple layers can be madeby repeating the method described infra. The pressure chamber can beheated, for example, to decrease the viscosity of and decrease themodulus of the panels.

FIG. 18F shows a cross section of 32E with the mandrel 230 omitted. Theprocess in FIGS. 18A through 18E may be repeated on the part shown inFIGS. 18E and 18F to produce the bladder 52 cross section shown in FIG.18G. Panels 196 c and 196 d may be formed. Each panel may have anadhesive 208 c and 208 d facing radially inward. Balloon third andfourth internal seams 69 c and 69 d may be oriented about midway betweenballoons first and second internal seams 69 a and 69 b. The bladder 52may be leak tight. Alternatively, the inner layer can be a blow-moldedballoon, which is well-known in the art. The balloon can be filled withmedia (gas, liquid, or solid) during the winding process.

Referring to FIG. 16, the fiber 85 can then be applied over the bladderor mandrel. The fiber 85 can be applied, for example, using an automatedhead configured to run the fiber across the surface of the bladder ormandrel. FIG. 16 illustrates that fiber 85 can be wound over a mandrel230 (which can include bladder or other layers thereon) using a toolwheel 248. The fiber 85 may be continuous or discontinuous. The mandrelcan be rotated about the mandrel longitudinal axis 250 or balloonlongitudinal axis. The mandrel can be rotated, for example, in a singledirection throughout the entire fiber-laying process so as to obtain thefiber pattern depicted in FIG. 1.

The spool 244 can be passively (e.g., freely) or actively rotated,deploying fiber 85. Before or during winding, the fiber 85 may beinfused or coated with an adhesive, a solvent, or both. A tool arm 246can be attached to a rotating tool wheel 248. The tool arm 246 canrotate and translate to position the tool wheel 248 normal to and incontact with the inflatable device 2. The tool wheel 248 can applypressure normal to the surface of the inflatable device 2 so as to helpattach the fiber 85 to the surface upon which it is being applied and/orspread monofilaments of the fiber tow across the device. The tool wheel248 may help to adhere the fiber 85 to the inflatable device 2, forexample by applying pressure and following closely the surface of theinflatable device 2 or mandrel 230. The tool wheel 248 can be heated tosoften or melt the material on the surface of the balloon 20. Anotherheat source or a solvent may be used to tack the fiber in place, to meltor solvate a material on the balloon, to melt or solvate a material onthe fiber or combinations thereof. A separate resistive heater, a laser,a UV light source, an infrared light source, a source of hot air, or anRF welder may be used with or without the tool wheel 248 to attach thefiber. A solvent such as methyl ethyl ketone or tetrahydrofuran oralcohol or combinations thereof may promote adhesion of the fiber 85 andmay be used with our without the tool wheel 248. The tool wheel 248 canbe made of or coated with a non-stick material. The tool wheel 248 maynot rotate. The tool wheel 248 may comprise a hard surface, for examplecarbide. In some embodiments, a nozzle having a hard surface can be usedin place of the tool wheel 248.

In some embodiments, an adhesive or thermally weldable material, such asthermoplastic polyurethane (TPU), can be applied to the bladder to helpstick the fiber thereto. Further, in some embodiments, the fiber can bedipped through a solvated adhesive or thermally weldable material, suchas TPU, during the application. In some embodiments, the material can beapplied by spraying. In cases where both solvated thermally weldablematerial and thermally weldable material on the bladder are used, thenative thermally weldable material can advantageously meet the solvatedthermally weldable material to help aid the adhesive properties.Adhesive or thermally weldable material can be applied duringapplication of fiber or after the wind is concluded.

Further, in some embodiments, an outer layer can be applied over thefiber wind. The outer layer can be formed, for example, of a panel orpanels of film wrapped around the fiber-covered device, similar todescribed and shown with respect to FIGS. 18A-18E.

In some embodiments, the inner or outer layers described herein can beformed by deposition. For example, a metal such as gold (or othermaterials listed herein) may be deposited to form a layer. The layersmay be formed by vapor deposition, such as physical vapor deposition,chemical vapor deposition or combinations thereof. For example,materials such as parylene, polyimide, polynapthalene, PolyphenyleneVinylenes, fluoropolymer blends, Polyazomethine,poly-fluorohydrocarbons, poly-perfluorocarbons, polyolefins, orcombinations thereof may be deposited. Vapor deposited layers canadvantageously be pinhole free, thereby enhancing the leak-resistance ofthe inflatable device. Furthermore, vapor deposition allows for thelayers to be easily mass-produced.

After all of the layers of the wall 1331 have been applied to themandrel, the wall 1331 can be consolidated. For example, referring toFIGS. 19A-19B, the inflatable device 2 before final consolidation may beplaced in a balloon mold 622 containing a balloon pocket 624. Theballoon mold may be textured or porous such that substantial amounts ofgas may be drawn from balloon pocket 624 through or along the wall ofballoon mold 622 and out into the surrounding atmosphere. The balloonmay have a tube placed in its inner volume that may extend out eitherend of the balloon 622 (not shown). The tube may be thin and veryflexible. The tube may be a silicon rubber. A coating may be sprayedinto mold 622 that bonds to the balloon during cure to form an outerlayer 72 a on the balloon 2.

FIG. 19B illustrates that the balloon mold may be closed around theinflatable element 2. Pressure may be applied thru balloon second fluidport such that the balloon expands to contact the inside of balloonpocket 624. Alternately, the tube extending out either end of theballoon (not shown) may be pressurized to force the balloon into contactwith pocket 624.

Mold 622 may be placed in an oven and heated. Mold 622 may have built inheaters. The balloon mold may be placed under vacuum or placed in avacuum chamber during heating. Heating the balloon under pressure maycause one or more layers or sections to melt and/or fuse and/or bondwith adjoining layers or sections. The melting under pressure may removevoids or pockets in the balloon wall. The outer inner and outer layers(72 b, 72 a) may not melt. Heating the balloon under pressure may causethe wall 1331 of the inflatable device 2 before final consolidation tofuse or laminate into one continuous structure. The balloon outer wall22 b and/or outer layer 72 a may be substantially smoothed by thisprocess. The balloon outer wall 22 b and/or outer layer 72 a may bepermeable or perforated such that gas or other material trapped in theballoon wall 22 during manufacture may escape when the balloon is heatedunder pressure.

The fibers described herein can be made from a variety of materials.Exemplary materials include Vectran®, PBO, Spectra®, Conex®, Dyneema®,Technora®, Dacron®, Compet®, Polyester, Nylon, PEEK, PPS, Boron Fiber,Ceramic Fiber, Kevlar®, Inorganic Carbon or Carbon fiber, Inorganicsilicon or high strength fiberglass, Organic polymer or aramid, Twaron®,Tungsten, Molybdenum, Stainless Steel, Nickel/cobalt alloys, Titaniumalloys, and Nitinol alloys.

The inflatable devices 2 described herein can be used as medicalinvasive balloons, such as those used for transcutaneous heart valveimplantation are disclosed. For example, those balloons used fortranscatheter aortic-valve implantation. Inflatable device 2 may also beused for angioplasty in both coronary and peripheral applications.

In one exemplary embodiment, an inflatable medical device for use in BAVcan have a diameter of approximately 20 mm, a burst pressure of around10 atm, 40 tows per inch lengthwise in the central portion (about 126tows in a one-inch diameter balloon), and 60 tows per inch in the hoopwind in the central portion. The tow can have 8 mono-filaments and abreak strength of about 1.4 lbs.

Advantageously, the inflatable device described herein is configured tohelp prevent helical or circumferential failures. That is, because thefibers extend substantially parallel to the longitudinal axis within thecentral portion of the device (which has the largest diameter), thedevice is most likely to fail along those parallel fibers in the centralportion. Such failure substantially along the longitudinal axis canadvantageously allow for ease of pull-out through a sheath orintroducer. Should the central portion be helically wound, hoop fiberscan be deposited at or near the shoulder such that the burst failurewould be helical, but constrained to an increasingly narrow centralzone.

Furthermore, the fiber strands of the inflatable device described hereincan be laid down continuously with minimized tooling. The process can beautomated and easily updated. The fiber application process can beperformed quickly, particularly the application of the strands parallelto the longitudinal axis. Further, since the path of the machine iscontrolled by a computer running software, the automated process allowsfor ease of changeability between different size and shapes ofinflatable devices. After a device is loaded, the application of all thefiber can be accomplished automatically, with no need for humanintervention.

The inflatable device described herein can further be engineered to havefiber deposition that exhibits minimized internal wall shear. Wall shearmay lead to “slumping” of fiber, wherein fibers, particularly hoopfibers, travel from larger radius sections to smaller radius sectionswhen the balloon is inflated. Travel of hoop fibers may cause prematurefailure of the balloon and thus limit the balloon's maximum inflationpressure.

The fiber strands of the inflatable device described herein furtherallow for a decreased build-up of fibers at the ends of the balloonrelative, for example, to a balloon wound with a helix pattern.

The fibers for the inflatable device described herein are furtheradvantageously applied using slight tension throughout the entireapplication process, thereby helping to ensure that fiber doesn't liftor move during application.

Any elements described herein as singular can be pluralized (i.e.,anything described as “one” can be more than one), and plural elementscan be used individually. Characteristics disclosed of a singlevariation of an element, the device, the methods, or combinationsthereof can be used or apply for other variations, for example,dimensions, burst pressures, shapes, materials, or combinations thereof.Any species element of a genus element can have the characteristics orelements of any other species element of that genus. The above-describedconfigurations, elements or complete assemblies and methods and theirelements for carrying out the invention, and variations of aspects ofthe invention can be combined and modified with each other in anycombination.

The invention claimed is:
 1. A medical apparatus, comprising: a balloonincluding a central portion and first and second tapered portionsconnected to the central portion, the balloon including a longitudinalaxis extending from a first end of the balloon to a second end of theballoon; and a single continuous fiber extending substantially parallelto the longitudinal axis along the central portion and circumferentiallyaround at least one of the first and second tapered portions or thecentral portion of the balloon; and a second fiber extendingcircumferentially around the central portion of the balloon, the secondfiber being part of the single continuous fiber.
 2. The apparatus ofclaim 1, wherein the single continuous fiber comprises a plurality offirst fiber strands.
 3. The apparatus of claim 2, wherein each strand ofthe plurality of first fiber strands extends at an angle ofapproximately 35-90 degrees relative to the longitudinal axis of theballoon as the plurality of first fiber strands extend around at leastone of the first and second tapered portions.
 4. The apparatus of claim2, wherein each strand of the plurality of first fiber strandstransitions from extending around the first and second tapered portionsto extending substantially parallel with the longitudinal axis in atleast one of the first and second tapered portions.
 5. The apparatus ofclaim 1, wherein the second fiber extends at an angle of approximately80 to 90 degrees relative to the longitudinal axis of the balloon as thesecond fiber extends around the central portion.
 6. The apparatus ofclaim 1, wherein the second fiber extends around at least one of thefirst and second tapered portions at a lower pitch than a pitch of thesecond fiber strand around the central portion.
 7. The apparatus ofclaim 1, wherein the second fiber extends over the first fiber.
 8. Theapparatus of claim 7, wherein the second fiber extends over a firstportion of the first fiber and under a second portion of the firstfiber.
 9. The apparatus of claim 8, wherein the first portion of thefirst fiber is on a first half of the balloon and the second portion ofthe first fiber is on a second half of the balloon.
 10. The apparatus ofclaim 1, further comprising a third fiber starting in the first taperedportion at a location separated from the first end of the balloon. 11.The apparatus of claim 10, wherein the third fiber is part of the singlecontinuous fiber.
 12. The apparatus of claim 1, wherein the singlecontinuous fiber extends around both the first and second taperedportions of the balloon.
 13. The apparatus of claim 1, wherein thesingle continuous fiber has a turn around on at least one of the firstand second tapered portions.
 14. The apparatus of claim 1, wherein thesingle continuous fiber has first and second turn arounds on at leastone of the first and second tapered portions.
 15. A fiber-reinforcedmedical balloon comprising: a generally cylindrical central portion;first and second generally conical portions connected to the generallycylindrical central portion along a central longitudinal axis extendingfrom a first end of the balloon to a second end of the balloon; aplurality of first fiber strands extending from the first end of theballoon to the second end of the balloon, each strand of the pluralityof first fiber strands running substantially parallel to thelongitudinal axis through the generally cylindrical central portion andpartially around at least a conical part of the first and secondgenerally conical portions; and at least one second fiber strandextending circumferentially around the generally cylindrical centralportion; wherein the plurality of first fiber strands and the at leastone second fiber strand are all part of a single continuous fiber. 16.The fiber-reinforced medical balloon of claim 15, wherein the at leastone second fiber strand extends around the first and second conicalportions at a lower pitch than a pitch of the at least one second fiberstrand around the central portion.
 17. The fiber-reinforced medicalballoon of claim 15, wherein the at least one second fiber strandextends over the plurality of first fiber strands.
 18. Thefiber-reinforced medical balloon of claim 15, wherein the at least onesecond fiber strand extends over a first portion of the plurality offirst fiber strands and underneath a second portion of the plurality offirst fiber strands.
 19. The fiber-reinforced medical balloon of claim18, wherein the first portion of the plurality of first fibers are on afirst half of the balloon and the second portion of the plurality offirst fibers are on a second half of the balloon.
 20. Thefiber-reinforced medical balloon of claim 15, further comprising aplurality of third fiber strands, the plurality of third fiber strandsstarting in the first generally conical portion at a location separatedfrom the first end of the balloon.
 21. The fiber-reinforced medicalballoon of claim 20, wherein at least a portion of the first fiberstrands and the third fiber strands are part of a single continuousfiber.
 22. A medical apparatus, comprising: a balloon including acentral portion and first and second tapered portions connected to thecentral portion, the balloon including a longitudinal axis extendingfrom a first end of the balloon to a second end of the balloon; and asingle continuous fiber including a first portion extendingsubstantially parallel to the longitudinal axis along at least oneportion of the balloon and a second portion extending generallyperpendicular to the longitudinal axis along at least one portion of theballoon, the first and second portions of the single continuous fiberextend over both the central portion and the first and second taperedportions of the balloon.